JP2001266362A - Recordable optical disk and its recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the alteration of important control data or the like not to be altered, recorded in a control data zone or the like, by recording important information common to a read-only DVD-ROM or the like and a writable DVD- ROM or the like in the same zone on both disks. SOLUTION: A recordable optical disk is provided with a disk substrate, a recording track formed spirally or concentric-circularly around the center of the disk substrate, an embossed pit formed in a specified area on the disk substrate so as to have a correlation with specified data recorded on the recording track in the specified area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a recordable optical disk and a recording method thereof.

[0002]

2. Description of the Related Art Due to the diversification of the CD (Compact Disc) format and the emergence of DVDs, optical discs include:
There are various types. At present, the CD includes a read-only CD-ROM (CD-Read Only), a CD-R (CD-Recordable) that can be written only once, and a CD-RW (CD-Rewritable) that can be written many times. . DVD includes
Read-only DVD-ROM (DVD-Read Only), 1
DVD-R (DVD-Recordable) that can be written only once
DVD-RW (DVD-Re-recor
dable), DVD-RAM (DVD
-Rewritable).

By the way, information important only for a DVD-ROM is written in a control data zone of the DVD-ROM. In a zone of the DVD-RW located at the same position as the control data zone, an unreadable emboss that disables both reading and recording in this zone is formed in order to prevent data falsification ( Embedded). Therefore, DVD
On the -RW, control data is written in a zone different from the control data zone of the DVD-ROM.

[0004]

However, considering the possibility of writing important information common to both read-only DVD-ROMs and the like and recordable DVD-RWs that should not be tampered, on both disks in common. In such a case, it becomes necessary to record such important information in the same zone on both disks. As described above, it is extremely difficult to meet such a need while preventing the tampering of such important information on a recordable optical disk by forming an unreadable emboss.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a recording capability capable of preventing data recorded in a predetermined area from being tampered while enabling reading of predetermined data recorded in the predetermined area. It is an object to provide an optical disk and a recording method thereof.

[0006]

According to a first aspect of the present invention, there is provided a recordable optical disk, comprising: a disk substrate;
A recording track formed spirally or concentrically around the center of the disk substrate, and formed in a predetermined area on the disk substrate in correlation with predetermined data recorded on the recording track in the predetermined area. It has an embossed pit.

According to the recordable optical disk of the present invention,
Since the data pattern of the predetermined data is known in advance,
The emboss pit is formed in a predetermined area in correlation with predetermined data to be recorded in the predetermined area. Then, the predetermined data is recorded in a predetermined area where the emboss pit is formed. Here, although the predetermined area has the emboss pits, the predetermined data has a correlation with the emboss pits, so that the writing and reading of the predetermined data can be performed normally. On the other hand, since the non-predetermined data has no correlation with the emboss pit, the non-predetermined data cannot be normally written or read in the predetermined area. That is, even if an attempt is made to falsify predetermined data, recording marks and recording spaces of such non-predetermined data appear at a boundary between the recording marks and the recording spaces with a high probability, and in the middle of the recording marks and the recording spaces. The signal level is affected with a high probability by the presence of embossed pits that shift the signal level so that it cannot be ignored.

By forming emboss pits having a correlation with predetermined data in a predetermined area in this way, the reflectance is intentionally reduced in the predetermined area due to the presence of the emboss pits. Ends in failure. On the other hand, for (regular) predetermined data, writing and reading can be normally performed regardless of the decrease in the reflectance.

In one aspect of the recordable optical disk of the present invention, the emboss pit is formed so as not to exist at a boundary between a recording mark of the predetermined data and a recording space.

According to this aspect, the emboss pit does not exist at the boundary between the recording mark of the predetermined data and the recording space. That is, the length of the emboss pit along the recording track is shorter than the length of the recording mark or recording space along the recording track. Therefore, it is possible to normally write and read the predetermined data without depending on the reflectance reduction caused by the embossed pits.

In another aspect of the recordable optical disk according to the present invention, the emboss pit is formed at a position where a length of the recording mark of the predetermined data along the recording track is equal to or longer than a predetermined length.

According to this aspect, the length of the emboss pit along the recording track of the recording mark of the predetermined data is:
Since it is formed at a position that is longer than a predetermined length (for example, 8T, 4T, etc. (where T is a basic clock cycle)),
By forming the emboss pit having a length shorter than the recording mark and longer than the basic clock cycle (for example, 4T, 2T, etc.), it is possible to more reliably prevent the predetermined data from being falsified.

In this aspect, the length of the emboss pit may be constant regardless of the length of the recording mark.

With this configuration, the emboss pit can be formed relatively easily.

Alternatively, in this aspect, the length of the embossed pit may change according to the length of the recording mark.

With this configuration, the margin of the embossed pit with respect to the end of the variable-length recording mark can be maintained. That is, the longer the recording mark, the longer the emboss pit, and the shorter the recording mark, the shorter the emboss pit,
Maintain a moderate margin in the embossed pit.

In another aspect of the recordable optical disk of the present invention, the emboss pit is formed at a position where a length of the recording space of the predetermined data along the recording track is equal to or longer than a predetermined length.

According to this aspect, the emboss pit is formed at a position where the length of the predetermined data recording space along the recording track is equal to or longer than the predetermined length (for example, 8T, 4T, etc.). A length shorter than the recording space and longer than the basic clock cycle (for example, 4T, 2T)
By forming embossed pits with
It is possible to more reliably prevent the predetermined data from being falsified.

In this aspect, the length of the emboss pit may be constant regardless of the length of the recording space.

With this configuration, emboss pits can be formed relatively easily.

Alternatively, in this aspect, the length of the emboss pit may change according to the length of the recording space.

With this configuration, the margin of the emboss pit with respect to the end of the variable length recording space can be maintained. That is, if the recording space is long, the emboss pit is lengthened, and if the recording space is short, the emboss pit is shortened, and an appropriate margin in the emboss pit is maintained.

In another aspect of the recordable optical disk according to the present invention, the predetermined area is in a control data area, and the predetermined data is different from the predetermined area in a data recording area in which the emboss pit is not formed. This is control data for controlling a recording / reproducing operation for data recorded on the recording track.

According to this aspect, it is possible to prevent the control data recorded in the control data area from being falsified. Data such as video data and audio data in the data recording area is recorded or reproduced according to the control data.

Incidentally, such a control data area is, for example, in a lead-in area.

With this configuration, it is possible to prevent the control data in the control data area in the lead-in area from being falsified.

In another aspect of the recordable optical disk of the present invention, data other than the predetermined data is recorded on the recording track in a data recording area different from the predetermined area and in which the emboss pit is not formed. .

According to this aspect, data such as video data and audio data can be normally recorded and reproduced in the data recording area where no emboss pit is formed.

In another aspect of the recordable optical disk of the present invention, the optical disk further comprises a recording layer formed on the disk substrate, and the data including the predetermined data is recorded on the recording track by the recording layer. You.

According to this aspect, data including predetermined data such as control data in addition to video data and audio data is reliably recorded on a recording track by the recording layer.

Incidentally, such a recording layer may be made of a material which enables a recording operation which can be rewritten many times. In this case, a recordable optical disk such as a DVD-RAM can be realized. The recording layer may be made of a material that enables a recording operation that can be rewritten only once. In this case, a recordable optical disk such as a DVD-R can be realized. Alternatively, the recording layer may be made of a material that enables a recording operation that can be rewritten only a predetermined number of times. In this case, a recordable optical disk such as a DVD-RW can be realized.

According to another aspect of the present invention, there is provided a method for recording data on a recordable optical disk (including various aspects thereof) according to the present invention. Forming the embossed pits on the disk substrate; and recording the predetermined data in the predetermined area where the embossed pits are formed.

According to the optical disk recording method of the present invention,
First, emboss pits are formed in a predetermined area in correlation with predetermined data to be recorded in the predetermined area.
Next, the predetermined data is recorded in a predetermined area where the emboss pit has already been formed. Therefore, the operation of falsifying the predetermined data ends with a high probability of failure due to a decrease in reflectance caused by the embossed pits. On the other hand, with respect to the predetermined data, it is possible to normally write and read the data without depending on the reflectance reduction caused by the emboss pits.

In one aspect of the optical disc recording method of the present invention, a step of recording data other than the predetermined data on the recording track in a data recording area different from the predetermined area and in which the emboss pit is not formed is further included. Including.

According to this aspect, for example, after predetermined data is recorded in a predetermined area such as a control area in a lead-in area before shipment of an optical disk, video data,
Data other than predetermined data such as audio data is recorded in the data recording area by the user at home. Therefore, the data in the data recording area can be recorded and reproduced according to the predetermined data in the predetermined area that has not been tampered with.

The operation and other advantages of the present invention will become more apparent from the embodiments explained below.

[0037]

Embodiments of the present invention will be described below with reference to the drawings.

First, a physical configuration of a DVD, which is an example of a recordable optical disk of the present invention, will be described with reference to FIGS. 1 is an external perspective view of a DVD, FIG. 2 is a partially enlarged perspective view of a recording track portion of a transparent substrate constituting the DVD, and FIG.
FIG. 2 is a partial cross-sectional view of a recording track of a DVD.

In FIG. 1, a DVD 100 which is an example of a recordable optical disk of the present invention has a center hole 103.
, And a spiral or concentric recording track 102 around the center hole 103. A clamping area CA, an R (recording) information area RIA and an information area IA which are clamped by a clamper when the DVD 100 is set in the information recording / reproducing apparatus are provided from the inside to the outside of the DVD 100. I have. In the information area IA,
A lead-in area LIA, a data recording area DRA, and a lead-out area LOA are provided in this order from the inside. The recording track 102 is formed not only in the information area IA but also in the R information area RIA.

As shown in FIG.
Is a land track L composed of a land that is convex on the transparent substrate 110 and is concave with respect to the reading or writing laser beam LB; and a land track L that is concave on the transparent substrate 110 and is reading or writing. And a groove track G composed of a groove that is convex with respect to. On the land track L, land pre-pits LPP are formed. The groove track G is wobbled at a predetermined frequency. The land pre-pit LPP is used to define a physical address on the recording track 102.

The land pre-pits LPP are used so that an operation of recording recording data on the groove track G (ie, data writing operation) and an operation of reproducing recording data from the groove track G (ie, data reading operation) are executed. The position of the optical pickup in the information recording / reproducing device is controlled based on the indicated information. The recording data and control data for controlling recording and reproduction of the recording data may be recorded on the land track L instead of or in addition to the groove track G.

As shown in FIG. 3, in the DVD 100, a recording layer 111 and a light reflecting layer 1 are provided on a transparent substrate 110.
12 and a protective layer 113 are laminated. Recording layer 1
For example, in the case of a DVD-R, 11 may be made of a dye or the like which is a material whose optical characteristics change when irradiated with a writing laser beam having a higher intensity than a reading laser beam. Alternatively, the recording layer 111 is, for example, D
In the case of a VD-RW, a DVD-RAM, or the like, it may be made of a phase-change material or the like whose phase changes between a crystalline phase and an amorphous phase according to a laser beam irradiation condition.

Next, the data structure of the data recorded on the DVD 100 will be described with reference to FIG.
FIG. 4 is a diagram schematically showing the data structure of the DVD 100.

In FIG. 4, an R-information area RIA is a power calibration area (Pow).
er Calibration Area (PCA) and Recording Management Area RMA (Recording Management A)
rea). The information area IA includes a lead-in area LIA, a data recording area DRA, and a lead-out area LOA.

Here, in the data recording area DRA, various contents data such as audio data and video data (hereinafter referred to as main data) and file management information for managing the main data as a file are recorded.

Power calibration area PCA
When the information recording / reproducing apparatus performs data writing, it is provided to adjust the light amount of the optical pickup or the like so that data writing can be performed in an appropriate operation state by performing test writing or the like.

Recording management area RM
In A, test result data in the power calibration area PCA is recorded.

In the lead-in area LIA, recording management data indicating physical information of the disk is recorded.

The lead-out area LOA is provided at the end position of the main data recorded in the data recording area DRA. (00) h in the lead-out area LOA
Is recorded. The recording start position of the lead-out area LOA changes according to the data amount of the main data.

Each of these areas PCA, RIA, LIA,
The area addresses of DRA and LOA and the recording address of the data correspond to the E address recorded in the land prepit LPP.
It is set according to the CC block address.

FIG. 5 is a diagram for explaining details of the data structure in the lead-in area LIA and the lead-out area LOA.

In FIG. 5, an initial zone is provided at the start position of the lead-in area LIA, and (00) h meaning blank is set in the initial zone. A reference code zone is provided subsequent to the initial zone. In the reference code zone, a channel bit pattern (3T-6T-
7T) is recorded. A code word in a conversion table predetermined as a channel bit pattern is repeated. Based on this channel bit pattern, an equalizer for the HF signal is adjusted. Subsequent to the reference code zone, a buffer zone (00) h is provided.

In the control data zone, the type of DVD standard (DVD-ROM, DVD-RA
M, DVD-RW, etc.) and part version, disc size and minimum read rate, disc structure (single-layer R
OM disk, 1-layer RAM disk, 2-layer ROM / RA
M disc, etc., recording density, data area allocation, presence or absence of burst cutting area, start sector of border zone, and the like.

A part of the control data zone is
The information area important only for the DVD-ROM is allocated to the zone where the information is recorded. Subsequent to the control data zone, a buffer zone (00) h is provided.

FIG. 6 shows the basic principle of an optical disk recording method according to the present invention. In FIG. 6, groove tracks, land tracks, and land pre-pits in the DVD-RW are conceptually shown along the time axis in the upper part of the figure, and the timing chart of the recording signal together with the emboss pits is shown in the lower part of the figure. Parts are shown corresponding to the upper part of the figure.

As shown in FIG. 6, in the case of DVD-RW, a land pre-pit method is adopted as a track format, and recording data is recorded on the groove track by irradiating the groove track with a laser beam. Record On the other hand, ECC block addresses are recorded in advance on land tracks by forming land prepits.

In FIG. 6, each hatched portion indicates a groove track, and each black painted rectangular portion on a land track indicates a land prepit. Also, the recording signal and the emboss pit for the minute portion A on the groove track are
It is enlarged and displayed as a timing chart in the lower part of FIG.

As shown in FIG. 7, the DVD 1 of this embodiment
In the case of 00 (for example, DVD-RW), the emboss pits are composed of intermittent groove tracks G separated by a transparent substrate portion at substantially the same level as the land tracks L in the control data zone.
That is, in the control data zone of the DVD 100,
The emboss pit is formed on the groove track G by the light beam L
B is convex. Therefore, the reflectivity of the groove track G decreases at the embossed pit. In FIG. 7, the regular recording mark is recorded in synchronization with the emboss pit so that the detection of the regular recording mark (that is, the recording mark originally originally recorded) is not practically affected by the emboss pit. I have. On the other hand, detection of a falsified recording mark (that is, a falsified recording mark that is not synchronized with the embossed pit) is affected by the embossed pit, as described later in detail with reference to FIGS. Receive. In FIG. 7, the wobble of the groove track G is omitted for convenience of description, and a light spot SP having a diameter larger than the width of the groove track G is formed from the light beam LB.

In the present embodiment, the data which is important only for the DVD-ROM and which is not to be tampered with is determined in advance, so that the emboss pits are formed in synchronization with the important data (they are embedded). ). Therefore, D
In the case of VD-RW, the reflectance when a laser beam is irradiated decreases due to the presence of embossed pits, but important data recorded in synchronization with the embossed pits is affected when read out. Not receive. Since this important data is synchronized with the embossed pit, it can be written so that it can be read normally. On the other hand, if an attempt is made to falsify this important data, the falsified data is no longer synchronized with the embossed pits, so that this data cannot be read normally. That is, since the falsified data is not synchronized with the embossed pit, important data cannot be falsified so that it can be read normally.

Furthermore, by forming a recording mark whose length along the recording track is relatively long or by forming an emboss pit in the center of the recording space, the start position or end position of data writing by the laser beam may be slightly shifted. Is hardly affected. In the present embodiment, the emboss pit is formed at the center of a recording mark or recording space where the recording pulse width is about 8T or more (where T is a basic clock cycle) or more. For example, as shown in the lower part of FIG. 6, an emboss pit is formed for each of the recording signals having a length of 8T, 13T, and 14T.

Further, if the embossed pit does not have a certain length along the recording track, the possibility that the end of the falsified data will affect the embossed pit will be reduced, and as a result, In such a case, the falsified data may be normally read. That is, the tampering is successful. Therefore, in this embodiment, emboss pits having a length of about 4T are formed for each of the recording marks and recording spaces having a length of 8T or more.

FIG. 8 is a diagram showing details of the timing chart shown in FIG. 6 in the recording method according to the first embodiment of the present invention.

That is, in FIG. 8, 8T along the recording track
A recording signal with embossed pits in both a recording mark having a length of 8T (hereinafter simply referred to as 8T mark) and a recording space having a length of 8T along the recording track (hereinafter simply referred to as 8T space) , Emboss pits, RF signals, and binarized signals. The embossed pit is preferably a DVD10
When the groove track, the land track, and the land prepit are formed on the transparent substrate 110 (see FIGS. 1 to 3) in the manufacturing process or the cutting process of No. 0, the embossing is performed on the transparent substrate 110. The emboss pit is embossed on the groove track if the recording signal is recorded on the groove track. Alternatively, the emboss pit may be embossed on the land track if the recording signal is recorded on the land track, or may be embossed on the groove track if the recording signal is recorded on both the groove track and the land track. And embossed on both land tracks.

In FIG. 8, since the recording signal is not a falsified one but a regular one, the recording signal and the emboss pit have a correlation (synchronized) with each other.

The 8T mark is 4T along the recording track.
Is recorded where embossed pits having a length of (hereinafter simply referred to as 4T embossed pits) are formed. However, not only 4T embossed pits but also 8T
Since the reflectivity of the 8T mark is also reduced by the mark itself, it is used to convert the RF signal into a binary signal and is lower than a threshold (threshold) level indicated by a dotted line over the RF signal in the figure. Up to the RF
The signal is double downed by 8T marks and 4T embossed pits. Therefore, the binarized signal relating to the 8T mark is not affected by the presence of the 4T emboss pit.

Actually, in the example shown in FIG. 8, even if the embossed pit is not formed in synchronization with the recording mark, the RF signal obtained at the recording mark depends on the existence of the recording mark itself. It has dropped to almost the lowest level. Therefore, in this example, the RF signal at the 8T mark that is lower than the threshold level is 4
Substantially unaffected by the presence of the T embossed pit. However, if the RF signal at the recording mark has not dropped to the lowest level, 8T
The RF signal at the mark may be further leveled down by the 4T emboss pit. In this case, the further reduction of the RF signal in the 8T mark due to the 4T emboss pit contributes only to the reduction of the RF signal below the threshold level as long as the recording mark is synchronized with the emboss pit. The principle of the present embodiment described above is still effective. Therefore, in this case, the binarized signal associated with the 8T mark is again a 4T mark.
Not affected by the presence of embossed pits.

In FIG. 8, the 8T space is located where another 4T embossed pit is formed. However, the decrease in the amount of reflected light in the 8T space due to the presence of the 4T embossed pit is small enough not to lower the RF signal below the threshold level. Therefore, the binarized signal corresponding to the 8T space is not affected by the presence of the 4T emboss pit.

FIG. 9 shows signal waveforms of a recording signal, an emboss pit, an RF signal, and a binary signal in a state where emboss pits are formed in the same manner as in FIG. 8 and the recording data is falsified.

In FIG. 9, since the recording signal has been tampered with illegally, the recording signal and the emboss pit no longer have a mutual correlation (are not synchronized).

One end of the 8T mark (that is, falsified recording data in this case) is located in one 4T emboss pit, and the other end of the 8T mark is located in another 4T emboss pit. Therefore, the amount of reflected light at the 8T mark decreases near these ends due to the presence of these 4T embossed pits. Accordingly, the RF signal level with respect to the threshold level is affected by the influence of these 4T embossed pits so as to be negligible. As a result, the binarized signal has an 8T mark, that is, a falsified recording data. In FIG. 9, as shown by the shift amount X and the shift amount Y, the shift is remarkable.

As is clear from FIGS. 8 and 9, according to the first embodiment, even if the recorded data is falsified in a predetermined area in which important data is recorded and which is not desired to be falsified, the falsification occurs. Recorded data cannot be read normally. That is,
Falsification of the recorded data results in failure. As described above, since the data is hardly falsified, the recording data in the predetermined area can be protected.

FIG. 10 is a diagram showing details of the timing chart shown in FIG. 6 in the recording method according to the second embodiment of the present invention.

That is, in FIG. 10, a recording signal in a state where 4T emboss pits are formed in the 8T mark and no emboss pits are formed in the recording space,
The signal waveforms of the embossed pit, the RF signal, and the binarized signal are shown.

In FIG. 10, since the recording signal is not a falsified signal but a regular signal, the recording signal and the emboss pit have a correlation (synchronized) with each other.

The 8T mark is recorded so as to overlap the 4T emboss pit.
The RF signal is double downed by the 8T mark and the 4T embossed pit to below the threshold level because the mark itself also reduces the reflectivity at the 8T mark. Therefore, 8T
The binarized signal related to the mark is not affected by the presence of the 4T embossed pit.

On the other hand, the recording space is located where there is no emboss pit. Therefore, the binary signal corresponding to the recording space is not affected by the presence of the emboss pit.

FIG. 11 shows signal waveforms of a recording signal, an emboss pit, an RF signal, and a binary signal in a state where emboss pits are formed in the same manner as in FIG. 10 and the recording data is falsified.

In FIG. 11, since the recording signal has been tampered with illegally, the recording signal and the emboss pit are
No longer correlated (not synchronized).

Since one end of the 8T mark (that is, the falsified recording data in this case) is located within the 4T emboss pit, the reflected light amount at the 8T mark is 4
Due to the presence of T embossed pits, it decreases near this end. Therefore, the signal level of the RF signal with respect to the threshold level is affected by the influence of the 4T embossed pits so as not to be ignored. That is, the RF signal is
Since the level is lowered by the presence of the 4T emboss pit at one end of the 8T mark, the binarized signal is
The mark, that is, the falsified recording data is shifted as shown by the shift amount Z in FIG.

In the second embodiment, since no emboss pit is formed in the recording space, the RF signal leveled down by the emboss pit in the recording space is located above the threshold level as in the first embodiment. There is no need to set the depth of the embossed pit as you do. Therefore, in the second embodiment, the depth of the emboss pits may be set deeper than in the first embodiment, and the depth may be set so deep that the RF signal in the recording space is lowered below the threshold level. Is preferred. By setting the depth of the emboss pit in this way, if the recording data is falsified,
The emboss pit synchronized with the T mark functions to shift the binarized signal extremely effectively.

As is apparent from FIGS. 10 and 11, according to the second embodiment, even if the recorded data is falsified in a predetermined area where important data is recorded and which is not desired to be falsified, the data is falsified. Recorded data cannot be read normally. That is, falsification of the recorded data results in failure. As described above, since the data is hardly falsified, the recording data in the predetermined area can be protected.

Next, a method of recording data on the DVD 100 having the above configuration will be described with reference to FIG.

As shown in FIG. 12, first, a laser cutting process is performed. That is, a photoresist 46 is formed on the glass substrate 45. Thereafter, the photoresist 46 is exposed to a light beam so as to form a pattern of the photoresist 46 corresponding to the groove track G, the land track L, the land pre-pits LPP, and the emboss pits (Step S1). Next, the exposed photoresist 46 is developed to form the pattern of the photoresist 46 on the glass substrate 45 (Step S).
2). Next, a stamper 47 (ie, a so-called stamper disk) is formed using the exposed photoresist 46 (step S3). Next, the groove track G,
DVD 100 having embossed pits in addition to land track L and land pre-pits LPP (for example, DVD 100)
-RW) is manufactured by replication using the stamper 47 (that is, manufactured as a so-called replication) (step S4). Next, a prewrite process is performed on the DVD 100. That is, control data and the like are recorded in a control data zone and the like by irradiating the laser beam LB (Step S).
5).

According to the present embodiment, steps S1 to S1
In the manufacturing process of the DVD 100 in No. 4, the predetermined data to be recorded in the prewrite process in step S5 is already known. Therefore, emboss pits synchronized with predetermined data to be recorded in the pre-write processing in step S5 are
It is formed in the manufacturing process of steps S1 to S4. Thereafter, in the pre-write process in step S5, that is, in the recording process before shipping, predetermined data synchronized with the emboss pits already formed in the manufacturing process in steps S1 to S4 is recorded.
Therefore, after the pre-write processing in step S5, for example, DV
After the shipment or purchase of the D100, even if an attempt is made to falsify predetermined data in a predetermined area such as a control data zone, the falsified data is not synchronized with the emboss pits and is affected by the emboss pits (see FIG. 8). 11), the data cannot be read normally.
On the other hand, after the DVD 100 is shipped or purchased, the data recording area DRA in the information area IA is read.
(See FIG. 1 and FIG. 4), the user can perform the writing and reading of the main data without any problem based on the regular control data.

As described in detail above, according to the present embodiment, by forming emboss pits, predetermined data such as important control data which is not desired to be falsified and recorded in a predetermined area such as a control data zone is falsified. Can be prevented. And read-only DVD
-While it is possible to record important information common to a ROM or the like and a writable DVD-RW or the like in the same area on both disks, the important data can be read normally, On the other hand, an optical disk that cannot perform illegal rewriting or falsification of such important data is realized.

In the embodiment described above, the length of the data pattern which is the length of the recording mark or recording space where the emboss pit is formed is not limited to 8T. Further, the length of the emboss pit is not limited to 4T. For example, it is possible to form emboss pits having a length of 2T along a recording track for a recording mark or recording space having a length of 4T along a recording track. In any case, the emboss pit has a correlation with the data pattern, and is shorter than the length of the data pattern along the recording track.

Further, the length of the emboss pit (for example, 1T to 12T) along the recording track is determined by the length of the recording mark or recording space (for example, 3T) along the recording track.
To 14T). As a result, the margin at the end between the embossed pits and the data pattern can be made constant throughout all the embossed pits, so that more reliable data protection can be achieved.

Further, according to the above-described embodiment, mainly D
Although the description has been given of the case where the present invention is applied to the VD-RW, the present invention can be applied to another recordable optical disk such as a one-time writable disk (for example, DVD-R).

The present invention is not limited to the above-described embodiment, but can be appropriately modified without departing from the spirit or spirit of the invention which can be read from the claims and the entire specification. A recordable optical disk and a recording method thereof are also included in the technical scope of the present invention.

[0090]

According to the optical disk and the recording method of the present invention, it is possible to read out predetermined data such as control data recorded in a predetermined area such as a control data zone while falsifying the predetermined data. Can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a DVD used in an embodiment of the present invention.
It is a perspective view of.

FIG. 2 is an enlarged partial perspective view showing a portion including a recording track of the transparent substrate of the DVD shown in FIG. 1;

3 is an enlarged partial cross-sectional view showing a portion including a recording track of the DVD shown in FIG. 1;

FIG. 4 is a diagram schematically illustrating a data structure of a DVD used in the embodiment.

FIG. 5 is a diagram showing a detailed structure of a lead-in area in FIG. 4;

FIG. 6 is a diagram showing a basic principle in a recording method of the optical disc of the embodiment.

FIG. 7 is a partially enlarged perspective view of a DVD showing a basic principle in a recording method of the optical disc of the embodiment.

FIG. 8 is a timing chart illustrating an operation example of a recording method according to the first embodiment.

9 is a timing chart showing an operation example when falsified data is written in the example shown in FIG. 8;

FIG. 10 is a timing chart illustrating an operation example of a recording method according to a second embodiment.

11 is a timing chart showing an operation example when falsified data is written in the example shown in FIG.

FIG. 12 is a process chart showing a DVD recording method in the embodiment.

[Explanation of symbols]

 100 DVD 102 Recording track 110 Transparent substrate 111 Recording layer 112 Light reflecting layer 113 Protective layer G Groove track L Land track LPP Land prepit LB Light beam

Claims (13)

[Claims] 1. A disk substrate, a recording track spirally or concentrically formed around a center of the disk substrate, and recorded on a predetermined region on the disk substrate on the recording track in the predetermined region. A recordable optical disk comprising: predetermined data; and embossed pits formed in correlation. 2. The recordable optical disc according to claim 1, wherein the emboss pit is formed so as not to exist at a boundary between a recording mark of the predetermined data and a recording space. 3. The emboss pit according to claim 1, wherein the length of the recording mark of the predetermined data along the recording track is equal to or longer than a predetermined length. Recordable optical disc. 4. The recordable optical disc according to claim 3, wherein the length of the emboss pit is constant regardless of the length of the recording mark. 5. The recordable optical disc according to claim 3, wherein a length of the emboss pit changes according to a length of the recording mark. 6. The device according to claim 1, wherein the emboss pit is formed at a position where a length of the recording space for the predetermined data along the recording track is equal to or longer than a predetermined length. Recordable optical disc. 7. The recordable optical disk according to claim 6, wherein the length of the emboss pit is constant regardless of the length of the recording space. 8. The recordable optical disc according to claim 6, wherein the length of the emboss pit changes according to the length of the recording space. 9. The data recording apparatus according to claim 1, wherein the predetermined area is in a control data area, and the predetermined data is different from the predetermined area and includes data on the recording track in a data recording area in which the emboss pits are not formed. Record
The recordable optical disc according to any one of claims 1 to 8, which is control data for controlling a reproducing operation. 10. The data recording apparatus according to claim 1, wherein data other than the predetermined data is recorded on the recording track in a data recording area different from the predetermined area and in which the emboss pit is not formed. A recordable optical disc according to any one of the preceding claims. 11. The apparatus according to claim 1, further comprising a recording layer formed on said disk substrate, wherein data including said predetermined data is recorded on said recording track by said recording layer. The recordable optical disc according to any one of claims 1 to 4. 12. A method for recording data on an optical disk for recording data on a recordable optical disk according to claim 1, wherein the emboss pits are formed on the disk substrate; Recording the predetermined data in the predetermined area where pits are formed. 13. The method according to claim 12, further comprising a step of recording data other than the predetermined data on the recording track in a data recording area different from the predetermined area and in which the emboss pit is not formed. Recordable optical disc according to the above.